am ready to pull the trigger on the 2018 MBP but facing the dilemma of whether to bump up the processor spec. Hoping to know if the top tier i9 processor can hold a sustained 4.8ghz turbo without throttling because if it can’t i’d probably just save the money and go with the default cpu
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Does top tier 15 inch 8950HK processor throttle
- Thread starter blackreplica
- Start date
- Sort by reaction score
But, 4.8 GHz is for turbo boost, right?
How long is an Intel processor designed to stay in turbo boost, and is that considered "throttling" if it drops out of turbo boost but maintains the full 2.9GHz clockspeed?
Pretty sure that turbo boost is meant for short periods of time, and only one processor core is enabled during boost. It stays in boost if needed, dropping out when no longer necessary.
How long is an Intel processor designed to stay in turbo boost, and is that considered "throttling" if it drops out of turbo boost but maintains the full 2.9GHz clockspeed?
Pretty sure that turbo boost is meant for short periods of time, and only one processor core is enabled during boost. It stays in boost if needed, dropping out when no longer necessary.
Trouble is if it can’t hold boost for more than a few seconds its really not worth the purchase is it. I’d reckon a well designed laptop in terms of cooling should be able to maintain 4.8 on a single core for at least a couple minutes and I’m hoping for at least that much on the 2018 MBP
Based on paper specs alone they're both 45w tdp and thus should both consume the same amount of power and produce the same amount of heat. The i9 is simply higher binned.
Realistically however if I were to bet money on it I'd say the i9 would consume slightly more power at higher clocks since it is more likely to use a higher voltage on the voltage table.
Now for real real answer: the i9 isn't worth it because the MacBook doesn't have an adequate cooling solution to keep any variant of the hexacore sustained load without throttling.
Realistically however if I were to bet money on it I'd say the i9 would consume slightly more power at higher clocks since it is more likely to use a higher voltage on the voltage table.
Now for real real answer: the i9 isn't worth it because the MacBook doesn't have an adequate cooling solution to keep any variant of the hexacore sustained load without throttling.
I'm inclined to agree with your last statement h however I'm waiting on more people receiving their units before I decide.
I'm definitely headed for 32gb ram and 1tb ssd....just left to decide on the processor
I do agree with others on that it will only be fast intermittently as temperature allows.
However, I saw an incredible performance thermal management gain on my maxed out 2.7 ghz i7 processor retina mbp by applying liquid metal thermal paste. It can maintain the turbo boost speed of 3.5ghz almost all the time. I cant wait to see what the result would be with i9 processor.
But the caveat is that I only had my mbp with liquid metal for only a year. There is a long term concern with gallium interacting with copper heatsink.
However, I saw an incredible performance thermal management gain on my maxed out 2.7 ghz i7 processor retina mbp by applying liquid metal thermal paste. It can maintain the turbo boost speed of 3.5ghz almost all the time. I cant wait to see what the result would be with i9 processor.
But the caveat is that I only had my mbp with liquid metal for only a year. There is a long term concern with gallium interacting with copper heatsink.
Best bet is to wait on the more unbiased reviews and analyse your work flow. The i9 is extremely performant for a mobile CPU, it's also power hungry and requires a lot of cooling.
My own hex core notebook with 8750H can pull as much as 90W under full Turbo. All the hex core CPU notebooks Turbo up aggressively then will roll back CPU frequency due to power design limitations.
Short burst tests only reveal short term performance. What needs to be seen is the long term performance illustrating the CPU's settling frequency, 3.4GHz upwards would be solid value.
The CPU's are 45W TDP, however this measured at the base frequency not maximum Turbo. The i9 will very likely far exceed 100W at maximum frequency, nor likely to hold full Turbo indefinitely.
Cooling is another factor, if inadequate the CPU will thermally throttle under load, irrespective of the PL-1 & PL-2 limits
Q-6
My own hex core notebook with 8750H can pull as much as 90W under full Turbo. All the hex core CPU notebooks Turbo up aggressively then will roll back CPU frequency due to power design limitations.
Short burst tests only reveal short term performance. What needs to be seen is the long term performance illustrating the CPU's settling frequency, 3.4GHz upwards would be solid value.
The CPU's are 45W TDP, however this measured at the base frequency not maximum Turbo. The i9 will very likely far exceed 100W at maximum frequency, nor likely to hold full Turbo indefinitely.
Cooling is another factor, if inadequate the CPU will thermally throttle under load, irrespective of the PL-1 & PL-2 limits
Q-6
You can disable turbo boost using disabling app like Turbo boost switcher. And I think liquid metal will definitely help with the thermal management (ofcourse one should do this after warranty is over)
Better to undervolt the CPU. Liquid metal, is IMHO more trouble than it's worth as it can and does migrate and requires regular replacement. Better to use a good quality noncondutive paste designed for notebooks.
Q-6
Is there an application that you could use to undervolt CPU in MacOS? I'd love to know if there is!
I had my 2012 rmbp with Grizzly liquid metal for a year and it seems to be holding on pretty good. But I have to admit the small anxiety of how Gallium of the liquid metal will affect in the next few years.
But I get constant turbo boost thanks to large temp overhead as a tradeoff to the anxiety!
A few weeks back a member discussed undervolting Mac's and he was using a proprietary application native to OS X, and unfortunately I don't have a link back to the post.
Found itt
http://volta.garymathews.com/faq.html
Q-6
Last edited:
No idea for how long the i9 would be able to maintain turbo boost, but I’m fairly sure that it’s going to be a good deal faster than any other CPU ever used in the MBP. And that is what is relevant. Looking at frequencies is pointless if you lack the context. The theoretical single core boost is almost impossible to maintain since there is no such thing as single-thread operation in a modern OS anyway. Bottom line:if you need CPU power, the i9 is the way to go.
Moreover, still using USB-C for power supply so they had to stick to mediocre GPUs...so throttling problems should be less present when compared to laptops with more power hungry GPU (nVidia), given that there is a lot less total heat to dissipate inside the sistem....